|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Materials Research in Reduced Gravity
||In Situ Investigation of the Effects of Gravity Level Variations on the Directional Solidification Microstructures during Parabolic Flights
||Lara Abou-Khalil, Georges Salloum-Abou-Jaoude, Guillaume Reinhart, Christph Pickmann, Ylva Houltz, Jianning Li, Olle Janson, Henri Nguyen-Thi, Gerhard Zimmermann
|On-Site Speaker (Planned)
In the framework of an ESA-MAP project entitled XRMON, directional solidification experiments of Al-20wt%Cu with in situ and real time X-ray radiography were carried out during Parabolic Flight campaigns. Parabolic flights offer successions of periods with different gravity levels, allowing the investigation of the impact of gravity level variations on the solidification microstructure formation.
Directional solidifications of refined/non-refined Al-20wt%Cu alloys were investigated in a dedicated apparatus for a wide range of cooling rates and a constant temperature gradient. X-ray radiography was successfully used to observe the microstructure evolution, following the variations of gravity level.
For the non-refined sample, it was found that tip growth velocity is affected by the g-level change, while for the refined alloy a sharp increase of gravity level provokes a columnar-to-equiaxed growth. The most potent explanation of those effects is the variation of the liquid composition ahead of solid/liquid interface due to the hydrostatic pressure variation.
||Planned: A print-only volume